The methods and systems of the present invention are directed to the modification and improvement of transmissions for automotive vehicles of the type installed by the original equipment manufacturers. The invention is particularly directed to the improvement and modification of the automotive transmissions commonly known as the 200/4R-3 [manually operated] and the 200/4R-2 [automatic], both of which are "factory installed" in automotive vehicles manufactured by General Motors Corporation.
The present inventor owns U.S. Pat. No. 5,253,549, issued Oct. 19, 1993 and entitled "Methods And Systems For Improving The Operation Of Automatic Transmissions For Vehicles"; U.S. Pat. No. 4,790,938, issued on Dec. 13, 1988 and entitled "Filter For Removing Particulate Matter From Fluid Within A Movable Body"; U.S. Pat. No. 4,711,140, issued Dec. 8, 1987 and entitled "Throttle Valve System For Automatic Transmission"; U.S. Pat. No. 4,449,426, issued on May 22, 1984 and entitled "Laminated Separator Plate Means For Recalibrating Automatic Transmission" and U.S. patent application Ser. No. 08/333,552, filed Nov. 2, 1994 and entitled "Methods And Systems For Improving The Operation Of Transmissions For Motor Vehicles". The basic operation of transmissions for automotive vehicles is discussed in the aforementioned patents and patent application, and these patents and patent application are expressly incorporated by reference into the disclosure of the present patent application.
The basic principles of operation of the factory installed GENERAL MOTORS.RTM. 200-4R-2 and 200-4R-3 transmissions for automotive vehicles, including the specific modes of operation thereof and the hydraulic circuits and interrelationship of hydraulic circuits, are well known to those skilled in the automotive transmission art. Attention is respectfully invited to the operations manual and text entitled THM 200-R4, PRINCIPLES OF OPERATION, First Edition, (1980), published by General Motors Corporation, said publication describing in detail, among others, the operation of the "factory installed" 200-4R-2 and 200-4R-3 GENERAL MOTORS.RTM. transmissions, including a discussion of the structure, the hydraulic circuits, and the interrelationship between the structure and the hydraulic circuitry and fluid flow during normal operation of the transmissions in automotive vehicles. The disclosure of the aforementioned publication in its entirety is expressly incorporated by reference into the disclosure of the present patent application as disclosing and illustrating background material known to those of ordinary skill in the automotive transmission art.
Attached hereto as an Appendix is a publication entitled "TRANSGO 200/4R-2 & 3 REPROGRAMMING KIT", an instruction sheet describing the manner in which an automotive transmission mechanic implements the modifications to the 200/4R-2 and 200/4R-3 General Motors Corporation factory installed transmissions to achieve the goals of the present invention. The disclosure of the aforementioned instruction sheet in its entirety is also expressly incorporated by reference into the present patent application.
In the original design of the 200/4R-3 "factory installed" transmission, the first gear ratio cannot be obtained above a vehicle speed of approximately 28-30 miles per hour. (See the aforementioned GENERAL MOTORS Corporation publication). A primary object of the present invention is to enable the driver of the vehicle having a 200/4R-3 GENERAL MOTORS.RTM. transmission to select any available gear ratio at any time, thereby enabling the driver to obtain a "first" gear ratio whenever the gear selector lever is placed in the "1" position. This objective is accomplished by modification of the structure and operation of the existing hydraulic circuits of the original transmission and the addition of a new hydraulic circuits to the original transmission.
It is also desirable to modify the "factory installed" automotive transmission to result in quick application during upshifts and quick release forces during downshifts with minimum ratio sharing (overlap) during gear changes, for improved performance particularly when the vehicle is in heavy duty use. This object is obtained by varying the structure and operation of the hydraulic circuits of the original transmission to enlarge or reduce existing orifices to control the apply and release fluid flow through the hydraulic circuits, in conjunction with the modification of different spring and pressure values of the pre-existing hydraulic circuits of the factory installed transmission.
Other objects, improvements and advantages of the present invention will become apparent to those skilled in the art from the following description in conjunction with the drawings.